Making continuous joint between flat sheets

ABSTRACT

A method and apparatus for making a continuous joint between the longitudinal marginal edges of co-planar sheets wherein the sheets are advanced into the apparatus in co-planar relation with their adjacent margins overlapped. At a first station, both margins are bent down to provide a space between the sheets. At the next station, one margin is bent back so that at its edge a down-turned lip engages the down-turned margin of the other sheet. At a following station, the latter margin is wrapped about the lip to form an interlocked seam, and at a final station, the seam is flattened against the first margin. The apparatus includes pressing rollers above and below the plane of the sheets, the upper and lower rolls being coupled together at the first station in the space formed between the sheets.

Jan. 7, 1975 MAKING CONTINUOUS JOINT BETWEEN FLAT SHEETS 3,422,525 1/1969 Jeppson 29/200 B Primary Examiner-C. W. Lanham [75] Inventor: Knut Berg, Saltsjobaden, Sweden Assistant ExammerJames R. Duzan [73] Assignee: Aktiebolaget Svenska Flaktfabrikem, Attorney, Agent, or Firm D rfman, Herrell and Nacka, Sweden skill [22] Filed: Dec. 4, 1972 2] Appl. NO.2 311,766 [57] ABSTRACT A method and apparatus for making a continuous joint between the longitudinal marginal edges of co- [30] Forelgn Apphcauon Prmmy Data planar sheets wherein the sheets are advanced into the Dec. 9, Sweden apparatus in co planar relation thir adjacent margins overlapped. At a first station, both margins U-S- Cl. are bent down to provide a pace between the heets [5 e the next tation one margin is bent back so at Fleld of Search 55, 56, 57, 58, edge a down turned engages the down turned 13/514; 29/429 200 243-5, 509; margin of the other sheet. At a following station, the

138/156, 157, 163; 72/48, 51, 52 latter margin is wrapped about the lip to form an interlocked seam, and at a final station, the seam is flat- [56] References Clted tened against the first margin. The apparatus includes UNITED STATES PATENTS pressing rollers above and below the plane of the 2,025,750 12/1935 lngels 29/505 Sheets, the pp and lower r0115 being coupled 2, g2,350 7 1954 close 1 3 54 gether at the first station in the space formed between 2,950,697 8/1960 Flagler 113/54 the sheets. 3.319330 5/1967 Patry et a1. 113/54 3.407.640 10/1968 Lipp 113/54 2 ClalmS, l2 Drawmg Flgures 3 I la 2 4 MAKING CONTINUOUS JOINT BETWEEN FLAT SHEETS This invention relates to a method of continuously jointing two parallel surface elements of a thin material located in the same plane, either in the form of continuously advanced webs of optional length, preferably of thin sheet metal, or in the form of shaped metal sheets of optional size, by folding together said two surface elements one relative the other.

When such webs or surface elements are jointed to form surface elements of greater width, it has been usual heretofore either to manually work the original surface elements by means of tongues and similar tools, or by an edging machine to bring about flanged edges and, respectively, by a folding press to provide folds on the edges tobe jointed, and to out these surface elements to necessary lengths, whereafter the metal sheets cut off are manually moved in parallel on a working table, in such a way, that the surface elements are caused to overlap eachother and engage with each other during the final manual working of the fold by tools, which operation is completed by knocking down the fold to the same plane as the surface elements. This known method shows the disadvantage of being tedious and expensive as it requires the work of several persons and, besides, its result and the tightness of the joint de pend entirely on the skill of the persons carrying out the jointing operation. Arrangements are also known for jointing surface elements of the aforesaid kind by means of machines, for example as disclosed in the US. Pat. No. 3,422,525, according to which surface elements in the form of endless sheet metal webs are pretreated along abutting edge portions each by one set of pressing rollers. This known method requires an expensive equipment and, besides, it is complicated, because the sheet metal webs during the pre-treatment of the edge portion of each sheet metal web with associated active pressing rollers are to be supported on different levels before the pretreated edge portions are inserted one into the other, which is carried out in one and the same plane.

The present invention relates to a method, at which the disadvantages of the aforedescribed methods have been eliminated and which, besides, does not require a bulky arrangement for carrying out the method in a workshop.

The method according to the invention is characterized in that the surface elements in the initial phase of the method are positioned in their final positions relative one another such, that their plane edge portions in pairs overlap each other, that in a preparatory phase these edge portions are bent down and parted so that a free space is formed between said edge portions, that thereafter one edge portion is bent by lifting its outer portion to a position adjacent the second edge portion, whereafter both edge portions by successive deformation are brought into a position adjacent each other such, that said second edge portion projects past the first mentioned edge portion, about which said projecting edge portion thereafter is bent and folded, and the fold finally is placed down into a plane in parallel with the planes of the associated surface elements.

A preferred application of the method is characterized in that the surface elements at the beginning of the method are positioned in their final positions relative each other and fixed in these positions with their plane edge portions overlapping each other in pairs, whereafter the two edge portions during the advancing movement of the surface elements are bent down and simultaneously parted so much that said edge portions between themselves form a free space, that thereafter one, for example the left-hand one, of the two bentdown edge portions again is subjected successively to a bending upwards and simultaneously with its outer edge portion is lifted to a position adjacent the second edge portion, for example the right-hand one, and thereby the edge portions of the two surface elements are given such a position adjacent each other, that said second edge portion with its outer edge part projects past said firstmentioned edge portion, for example the left-hand one, about which the projecting edge portion, for example the right-hand one, thereafter is bent in steps and caused to enclose the firstmentioned edge portion, for example the left-hand one, to form a tight fold projecting from the surface elements thus jointed, and said fold thereafter is folded to a position planeparallel with the unitary plane of the surface elements now jointed.

The free space, according to an expedient application of the method, can be obtained by bending down in steps the lower edge portion of one surface element by a simultaneous soft rolling-down of the above-lying edge portion of the second surface element.

According to another advantageous application of the method, the fold whilst being closed is simultaneously knocked down successively to the plane common to the two surface elements.

The invention also comprises an arrangement for carrying out the method. The arrangement comprises a working table with pressing rollers supported in a beam and driven by a motor and, whenever applied, feed tables with roller conveyors on both sides of said working table for the surface elements, said table(s) along their lateral edges provided with movable control means. The arrangement is characterized in that the lower surface of the beam is located at a distance above the working table exceeding the total thickness of the overlapping edge portions of the surface elements, that the beam is connected with the working table by a beam holder having a length in the conveying direction of the surface elements somewhat shorter and a width somewhat smaller than the aforesaid free space between the bent-down and separated edge portions of the surface elements, that the pressing rollers located before said free space in the direction of feed of the surface elements are provided with a substantially horizontal axle and adapted to press down the upper edge portion as well as the lower edge portion, that one or more of the pressing rollers located closest after said free space also are provided with a substantially horizontal axle and adapted to lift only one edge portion to join closely the second edge portion, and the remaining pressing rollers located after the limited free space between the surface elements in the direction of feed of said elements are provided with an axle inclined to the horizontal plane or with a horizontal, alternatively vertical, axle and a bevelled surface on the respective pressing roller, followed by at least one pressing roller with a substantially horizontal axle and a substantially plane surface of the last pressing roller(s) supported in said beam.

The novel and improved method according to the invention for continuously jointing 'two parallel surface elements located in thesame plane is now described in greater detail, with reference to the different steps illustrated in the accompanying drawings, in which FIGS. l-A through l-J illustrate the steps of the method used in making a joint in accordance with the present invention;

FIG. 2 is a diagrammatic plan view of the preferred apparatus of the present invention; and

FIG. 3 is a view in cross section of the apparatus of FIG. 2.

A preferred arrangement for carrying out the method is illustrated in FIGS.'2 and 3 and also described in the following.

Two surface elements 1, 2 to be jointed are inserted in the direction of the arrows at A in the lower part of FIG. 2. The overlapping portions of the surface elements are designated by 1a and, respectively, 2a. This is illustrated by pos. l in FIG. 1. The first step for bringing about the free space, which is important for the method according to the present invention and designated by B in FIG. 1, is shownin pos. 2.

The free space is obtained by a soft rolling-down of the upper edge portion la-lb-lc of the surface element 1. This deformation, which implies a bending down by steps of the lower edge portion 2a, is illustrated in pos. 2 and pos. 3. Pos. 4 shows the temporary separation of the edge portion 1d, 1e on one side, and the edge portion Zn on the other side, and the effecting of the free space B. This step has rendered it possible for the surface elements 1, 2 to pass on both sides of the beam holder 20 (FIGS. 2,3), which constitutes the rigid connection between the working table and the pressing rollers 15, l6, 17 (FIGS. 2,3) supported on the beam 14 and located and active before the free space B and the pressing rollers 21, 22, 23, 24, 25, 26 (FIGS. 2,3). Pos. 5 shows how the left-hand edge portion with its parts If and lg is subjected to a successive deformation and with its outer edge part 1g is lifted to a position adjacent the second edge portion 2a. This lifting in completed state is illustrated in pos. 6. The right-hand edge portion projects past the left-hand edge portion, the bent-over end of which is designated by 1g. The next step in the jointing operation, according to pos. 7, is to bend in steps the outer end of the right-hand portion about the outer end 1g of the left-hand edge portion. The desired enclosure of the left-hand edge portion lg by the outer end 2c of the right-hand edge portion continues thereafter as illustrated in pos. 8 and 9. Pos. 9 and 10, besides, illustrate the successive folding down of the resulting fold to a position planeparallel with the unitary plane of the jointed surface elements 1,2. The completed fold is designated by 5.

The method has been described above with reference to a schematically shown continuous jointing of two optionally narrow or wide surface elements. These surface elements may, within the scope of the inventive idea, be parts of one side in a square duct or circular or oval pipe intended, for example, for a ventilation installation where high requirements with respect to tightness and accurateness to size are to be met even after the completion of the jointing. The method is highly attractive because of its wide application range in practice, due to the free space B. The only limiting factor is that the method is not adapted for jointing surface elements along a corner line of a square duct.

In FIGS. 2 and 3, which illustrate an embodiment of the apparatus seen from above and, respectively, by

way of a cross-section the following designations are used:

A feed of'surface elements 1,2

C discharge of surface elements 1,2

10 working table 7 11 upper plane surface of working table 12 stand or frame of working table 13 foundation of working table 14 beam 14a lower surface of beam 14b width of beam 14c length of beam 15 pressing roller for pos. 2

16 pressing roller for pos. 3

17 pressing roller for pos. 4

18 electric drive motor 19 cogwheel for power transmission from drive motor to pressing rollers 19a chains for power transmission between pressing rollers 20 beam holder 21 pressing roller for pos.

22 pressing roller for pos.

23 pressing roller for pos.

24-= pressing roller for pos.

25 pressing roller for pos.

26 pressing roller for pos. 10 v 27 left-hand conveying table 27a control means for surface element 1 28 roller conveyors 29 right-hand conveying table 29a control means for surface element 2 30 roller conveyors All pressing rollers are pairs of rollers, which are active above and, respectively, beneath the edge portions placed together and have a surface portion adjusted to the intended working moment on their circumference. The pressing rollers 15-17 work the edge portions of the surface elements downwards, and the pressing rollers 21-26 work the edge portions of the surface elements upwards, in relation to a plane through the surface elements 1,2.

In FIGS. 2 and 3 an apparatus is shown which corresponds to a complete equipment for carrying out the method at wide and, therefore, relatively heavy surface elements. When surface elements for square ventilation ducts or oval or circular pipes of a smaller width and, therefore, of a lighter weight are to be jointed, which as mentioned above lies within the scope of the invention, the conveying tables 27 and 29 can be abandoned, and, after a first setting, one man easily can guide such a duct or pipe on the working table 10 through the space below the lower surface 14 of the beam and the upper plane surface 11 of the working table for carrying out a jointing method identical to that described above.

I claim:

1. An apparatus comprising a working table having an upper surface and provided with pressing rollers, the upper rollers being supported in a beam and driven by a drive motor, and conveying tables coplanar with said upper surface and located on both sides of said working table with roller conveyors for work elements, said tables along their lateral edges provided with control means, for conveying the work elements along the plane of said tables in a straight-line path in which the inner edge portions overlap, the lower surface of the beam being located at a distance above the upper plane surface of the working table exceeding the total thickness of the overlapping edge portions of the work elements, the pressing rollers adjacent the feed end of said table operable to bend down said edge portions to separate them and form a free space between said work elements, the beam being connected with the working table by a beam holder in said free space having a length in the conveying direction of the work elements somewhat shorter and a width somewhat smaller than the aforesaid free space between the bent-down and separated edge portions the pressing rollers located immediately after said free space being provided with a substantially horizontal axle and adapted to lift only one edge portion to join closely the other edge portion, and the remaining pressing rollers located after the free space in the direction of feed of said elements being inclined to the horizontal plane to wrap said other free edge portion around said one edge portion and interlock the same, followed by at least one pair of pressing rollers with substantially horizontal axles and a substantially plane nip surface to flatten said interlocked positions into said conveying plane.

2. Apparatus for continuously joining two parallel surface elements of thin material located in the same plane comprising a working table, and means to advance the elements along said working table from the feed end to the discharge end thereof, said advancing means operable to feed in the elements in edgeoverlapping relation at the feed end, a beam overlying said working table and extending along the length thereof, roller means on said beam to press against the overlapping edge portions of the elements, means to drive said roller means concurrently with the advance of said elements, said roller means including a pair of pressing rollers having horizontal axes to deflect the overlapping edge portions of said elements downwardly out of said common plane to provide a free space between the bent-down portions, said beam being connected with the working table by a beam holder positioned intermediate the feed end and the discharge end of said working table in said free space, said roller means including pairs of pressing rollers on the discharge side of said holder including a pair having a horizontal axis adapted to lift one of said bent-down edge portions into said common plane and to form a downturned lip along the free edge of said portion, which lip is disposed closely adjacent the other bent-down edge portion, said roller means including rollers beyond said last mentioned pair having their axes inclined to the horizontal to wrap said other bent-down edge portion around said downturned lip of the lifted edge portion, and at least one pair of pressing rollers adjacent the discharge end of said table having horizontal axes to press back said downturned lip portion with a reverse bend to underlie said lifted edge portion to form a continuous joint with said wrapped-around portion. 

1. An apparatus comprising a working table having an upper surface and provided with pressing rollers, the upper rollers being supported in a beam and driven by a drive motor, and conveying tables coplanar with said upper surface and located on both sides of said working table with roller conveyors for work elements, said tables along their lateral edges provided with control means, for conveying the work elements along the plane of said tables in a straight-line path in which the inner edge portions overlap, the lower surface of the beam being located at a distance above the upper plane surface of the working table exceeding the total thickness of the overlapping edge portions of the work elements, the pressing rollers adjacent the feed end of said table operable to bend down said edge portions to separate them and form a free space between said work elements, the beam being connected with the working table by a beam holder in said free space having a length in the conveying direction of the work elements somewhat shorter and a width somewhat smaller than the aforesaid free space between the bent-down and separated edge portions the pressing rollers located immediately after said free space being provided with a substantially horizontal axle and adapted to lift only one edge portion to join closely the other edge portion, and the remaining pressing rollers located after the free space in the direction of feed of said elements being inclined to the horizontal plane to wrap said other free edge portion around said one edge portion and interlock tHe same, followed by at least one pair of pressing rollers with substantially horizontal axles and a substantially plane nip surface to flatten said interlocked positions into said conveying plane.
 2. Apparatus for continuously joining two parallel surface elements of thin material located in the same plane comprising a working table, and means to advance the elements along said working table from the feed end to the discharge end thereof, said advancing means operable to feed in the elements in edge-overlapping relation at the feed end, a beam overlying said working table and extending along the length thereof, roller means on said beam to press against the overlapping edge portions of the elements, means to drive said roller means concurrently with the advance of said elements, said roller means including a pair of pressing rollers having horizontal axes to deflect the overlapping edge portions of said elements downwardly out of said common plane to provide a free space between the bent-down portions, said beam being connected with the working table by a beam holder positioned intermediate the feed end and the discharge end of said working table in said free space, said roller means including pairs of pressing rollers on the discharge side of said holder including a pair having a horizontal axis adapted to lift one of said bent-down edge portions into said common plane and to form a downturned lip along the free edge of said portion, which lip is disposed closely adjacent the other bent-down edge portion, said roller means including rollers beyond said last mentioned pair having their axes inclined to the horizontal to wrap said other bent-down edge portion around said downturned lip of the lifted edge portion, and at least one pair of pressing rollers adjacent the discharge end of said table having horizontal axes to press back said downturned lip portion with a reverse bend to underlie said lifted edge portion to form a continuous joint with said wrapped-around portion. 